Welcome to my webpage. During my time at Kansas
State University I worked in the High Energy Physics Department under the
mentorship of Dr. Andrew Ivanov. My cohort, Alex Armstrong, and I worked with
some of the technology to be used on the new CMS
(Compact Muon Solenoid) detector at CERN on the LHC (Large Hadron

Collider). We primarily worked with an integrated
circuit chip called the Token Bit Manager (TBM for short).

About Me/Preface

Before
I discuss the details of my project, Iíd like to say a bit about myself. My
name is Wyatt Behn and I attend the University of Nebraska at Kearney as a physics
comprehensive major, a math and womenís studies minor. I am the current
president of our chapter of the Society of Physics Students (SPS), and I also
tutor math and physics for the university.

Below
I will describe the overview of my project and some of the tasks that I have
personally accomplished, as well as breakthroughs made by the research group as
a whole. Before that, Iíd like to preface this project by pointing out that
this research was more of a technical report than a groundbreaking new
discovery. Mostly, due to the high-level demand of experience and
specialization, I did not contribute directly to the construction or
programming of the circuits we worked with. Rather, the undergraduatesí main
focus was learning how research is conducted at CERN and the LHC itself and
being able to see physics in action. This was achieved vicariously through
independent study and coding practice, as well as reading code used on the TBM
chips we tested. This is not to say our entire experience was theoretical. Much
of our time was dedicated to testing TBM chips to insure their integrity and
functionality.

Disclaimer:
This program is funded by the National Science Foundation through grant number PHY-1157044.
Any opinions, findings, and conclusions or recommendations expressed in this
material are those of the author(s) and do not necessarily reflect the views of
the National Science Foundation.

Project Overview

Coding:
At the
beginning of our research there was much to learn. First, conquering the
programming language of C++ was crucial to our understanding of everything else
that Alex and I were to see during the remainder of our time at KSU. For the
first two weeks we created simple programs that captured the essence of the
functions we needed to comprehend for later use. The reason
why coding is so keystone to our research has to do with the nature of high
energy and particle physics, itself. Detectors that are built to find
and quantify the smallest of particles require a certain digital backbone that
allows them to carry out complex processes and convey the data in a meaningful
way. This is mostly achieved through computers and coding.

What is The LHC?:
The Large Hadron Collider (LHC) is the largest supercollider in the world; itís
located at CERN in Geneva Switzerland near the Alps. The LHC accelerates 2
beams of protons together into a collision point where a large detector gathers
information from the resulting chaos of particle showers. The most recent
discovery at CERN was the Higgs Boson particle validating the theorized Higgs
Mechanism of Mass. This discovery was revolutionary for the field of high
energy physics; however, one of the detectors at the LHC is due for an upgrade.
The CMS detector is one of four primary detectors at the LHC and it is a vital
part of accurately reconstructing the paths taken by particles in their
creation and subsequent decay. Small pixel detectors form several layers of a
barrel that is used to actually sense the particles as they pass through the
detector. The device that controls the pixel detectors is the Token Bit Manager
(TBM).

A cross section of the CMS detector with simple examples of
particle traversing it.

The TBM:
The Token
Bit Manager collects signals from the pixel detectors as new particles are
sensed, then TBM deems the data good or clears flawed data. We received a
number of these TBM chips on silicon wafers and some individual ones as well.
The chips themselves are very small (4.8 mm x 3.2 mm) and must be handled with
extreme care and tested with special probing equipment. It was the groupís task
to test these TBM chips to ensure they could complete their desired tasks
through simulations and to find their highest operating frequencies. These new
TBM chips, alongside the new and denser pixel sheets, will allow the LHC to
track and reconstruct particle collisions with even higher fidelity than ever
before.